Many applications benefit from an accurate count of people within a scene. Some of these applications may be used in combination with Heat Ventilation and Air Conditioning (HVAC) control systems, video surveillance systems, retail systems, and other fields. For example, an accurate count of people may provide statistics information for retailers to diagnose their advertisement effort, others may detect tailgating at a security check point. Municipalities may also use an accurate scene population count to determine the number of visitors at specific facilities. Counting people through use of visible spectrum and thermal cameras can result in inaccurate counts.